1. Field of the Invention
The present invention relates to a hybrid printer used in, for example, a POS (point-of-sales) system, and more particularly to a hybrid printer that is capable of printing on sheets of recording paper in various forms, such as, cut sheets of slip paper, rolled paper, thermal paper and the like.
2. Description of Related Art
A slip printer for printing on slips of paper, such as bills and the like, has been widely known. Since copies of an original paper may be required in printing by the slip printer, a serial printer that has a dot-impact type printing head is widely used as the slip printer.
Since there are a variety of slips of paper of different sizes, the slip printer, in many cases, has a paper transfer path which is opened at one end side thereof to accept slips of paper of different sizes. In other words, the paper transfer path has three opened sides in the paper feeding direction and at the one end side. Because of this, the slip printer often uses a structure in which a printing head and a mechanism for reciprocating the printing head are supported on a cantilever type frame.
Also, there are receipt printers for printing on sheets of receipt paper. One type of receipt printer using a thermal head for thermally printing on a rolled sheet of thermal paper is well known.
In recent years, the POS systems have become more popular. In this connection, hybrid printers incorporating at least the above-described two types of printers are on greater demand from the view point of reducing the required space in retail stores.
However, when the two printing sections are mounted in a common housing of the hybrid printer, the following problems arise.
When a printer having a plurality of printing sections is manufactured, each of the printing sections requires examination and adjustment (for example, adjustment of current pulse widths, adjustment of the platen gap and the like) specific to each of the printing sections. However, the examination and adjustment after completion of the entire assembly are not favorable from the viewpoint of the work efficiency. This results in a longer manufacturing time for completing each product.
Also, in the case of a breakdown of the printer, different parts for each of the printing sections have to be replaced, and independent repair work is required for each of the printing sections. As a consequence, it takes a longer time for the maintenance work.
Furthermore, the printer sections (e.g., a first printer section and a second printer section), that can be used in a hybrid printer, may be combined together and used in a hybrid printer, or may be used in an independent printer. In other words, there are cases of manufacturing a hybrid printer having the first and second printer sections, a printer having only the first printer section, and a printer having only the second printer section. For all of these printer types, a housing for covering each of the printer sections and a circuit board for controlling each of the printer sections are required. This is not favorable from the viewpoint of reducing the cost and shortening the delivery time.
From the view point of the required space reduction, a hybrid printer is preferably designed so that a receipt printing section for performing the receipt printing is disposed adjacent to a printing mechanism for a slip printing section for performing the slip printing. As a result, a cantilever for supporting the printing mechanism for the slip printing receives the weight of the receipt printing section in addition to the weight of the printing mechanism for the slip printing. Accordingly, the fixed end of the cantilever requires a substantial structural strength.
Moreover, the longer the cantilever that supports the printing mechanism, the more a difference in the platen gap (the distance between the printing head and the platen) between the fixed end and the free end of the cantilever likely occurs. When the platen gap is not accurately adjusted, the density of printed characters becomes uneven, resulting in a poor print quality. In other words, the heavier the load is applied to the cantilever, the greater the tendency of the poor print quality develops.
It is an object of the present invention to provide a low manufacturing cost hybrid printer that is easy to assemble and maintain. It is another object of the present invention to provide a hybrid printer that requires a smaller installation area.
In accordance with one embodiment of the present invention, a hybrid printer has a first printer, a second printer and a printer mounting base capable of mounting these printers which are structured in a manner described below. Also, the printers used in a hybrid printer in accordance with the embodiment of the present invention and the printer mounting base for mounting the printers have the following characteristics.
The first printer has a first printing section for printing on a first recording paper, a first transfer path for transferring the first recording paper to the first printing section, a first base having the first transfer path formed thereon, and a first cantilever for supporting the first printing section above the first base. For example, a serial impact type print head is used for the printing section of the first printer, and a cut sheet of paper is used for the first recording paper.
The second printer has a second printing section for printing on a second recording paper. In an embodiment, the second recording paper is a rolled sheet of thermal paper, and a thermal printer is used for the second printing section.
The printer mounting base has a second base, a second transfer path formed on the second base and a second cantilever fixed to the second base.
The second printer is mountable on the second cantilever of the printer mounting base. The printer mounting base is mountable in the rear of the first printer, and the second transfer path is disposed on an extension line of the first transfer path and continuous to the first transfer path.
In this manner, the second printer is mounted on the second cantilever provided on the printer mounting base, which is different from the first cantilever having the first printing section. As a result, an excessive weight is not applied to the first cantilever. In other words, the weight of the first printing section is received by the first cantilever and the weight of the second printer is received by the second cantilever. This structure therefore prevents deterioration of the accuracy of the platen gap, i.e., the distance between the first printing section and the platen provided in the first transfer path.
Also, the following manufacturing process can be implemented as a result of the above described structure. Namely, the first printer and the second printer are manufactured on independent manufacturing lines, and adjusted and examined, independently from each other. Then, the first and second printers can be mounted on a printer mounting base when assembling a hybrid printer. As a result, the work efficiency is improved. Moreover, even when one of the printers is broken, the broken printer can readily be removed from the other. Accordingly, the maintenance work becomes easier.
Also, the first printer has a fixing end section for supporting the first cantilever and a first guide section provided adjacent to the fixing end section for guiding a side edge of the first recording paper. The printer has a fixing end section for supporting the second cantilever and a second guide section provided adjacent to the fixing end section for guiding a side edge of the first recording paper. The guide sections are disposed so that the second guide section is disposed on an extension line of the first guide section and continuous to the first guide section when the first printer is mounted on the mounting base. As a result, cut sheets are securely and correctly guided along the first guide section and the second guide section.
Moreover, the first printer includes a housing that covers the first printing section and defines an aperture, a controller circuit for controlling the first printing section and a controller circuit for controlling the second printer. The second printer includes a housing that covers the second printing section and defines an aperture, and a driving device that drives the second printer. The apertures are located opposite to each other when the first printer and the second printer are mounted on the mounting base.
When a hybrid printer is manufactured by using the first and the second printers, the control device for controlling the second printer is connected to the driving device through the apertures.
On the other hand, when the first printer, that can be combined with the second printer, is manufactured as a stand-alone printer, a housing without an aperture is prepared, or the aperture may be closed by a cover. Also, when the second printer, that can be combined with the first printer, is manufactured as a stand-alone printer, a control board that has a controller circuit for controlling only the second printer and a second housing that covers the control board are prepared. The second housing is attached to an appropriate area, for example, the under side of the second printer.
Accordingly, when three types of printers including a hybrid printer are manufactured, many components including the housing, the circuit board and the like can be commonly used. As a result, the manufacturing cost is lowered, and different kinds of printers that meet the different demands can be manufactured in a relatively short delivery time.
Other features and advantages of the invention will be apparent from the following detailed description, taken in conjunction with the accompanying drawings which illustrate, by way of example, various features of embodiments of the invention.